The dissociative disorders are comprised of five psychiatric disorders which include: psychogenic amnesia, psychogenic fugue, depersonalization disorders, multiple personality disorder, and atypical dissociative disorder. Although these disorders were previously regarded as rare, current work suggests that this assessment is a misconception that has been perpetuated by the continued misdiagnosis of the most severe and chronic of the dissociative disorders, multiple personality. To date, there is no systematic diagnostic tool to assist in detecting the dissociative disorders. A reliable and valid instrument is needed, and the current study proposes to fill this need. Preliminary work on the development of the Structured Clinical Interview for DSM- III-Dissociative Disorders (SCID-D) suggests that the SCID-D has promise as a diagnostic tool. This project examines the reliability of the SCID-D in detecting dissociative disorders according to DSM-II-Revised criteria. The SCID-D will be tested at the Connecticut Mental Health Center on a sample of patients diagnosed with schizophrenia, major depression, dissociative disorders, and substance abuse disorders. One hundred and sixty subjects consisting of 40 in each of the four groups will be used in the reliability study. The SCID-D and three other tests will be administered by experienced clinicians trained for this purpose, using materials from the pilot phase of this project. The SCID-D will be administered a total of three times. Upon entrance into the study, subjects will be interviewed with the SCID-D. The SCID-D will then be administered two times subsequently, at intervals of 1-7 days and one year, for short and long-term reliability assessment. Reliability assessments will be made between raters and over time, both for overall diagnosis as well as separately for five specific global dissociative symptom areas. In addition to evaluating the inter-rater and temporal reliability of the SCID-D, we also will assess some psychometric properties (e.g., factor structure) of SCID-D items. Data from the other diagnostic tests also will be compared with the SCID-D evaluation in order to explore coexisting psychopathology in each of the four diagnostic groups. It is expected that the SCID-D will allow for the systematic and comprehensive assessment of the dissociative disorders, enabling researchers to accurately gauge incidence and prevalence, as well as to promote further epidemiological and clinical research of these disorders.